Transcript Nodes and Corridors

From insular protected areas to prioritised
biodiversity networks at a landscape level
On National Parks…they…
"have not drawn us into a more thoughtful relationship
with our habitat, They have not taught us that land is to
be used frugally and with good sense. They have
encouraged us to believe that conservation is merely a
system of trading environmental write-offs against large
protected areas. They more than failed; in fact they
have become a symptom of the problem"
(Van Tighem 1986).
This approach was paralleled by an approach where a single
umbrella, or charismatic species, was identified, and natural areas
put aside for its conservation
Ecosystems are now seen as producing indispensable benefits for the
economy, public health and general welfare of human beings
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regulation of the composition of atmospheric gases
regulation of the hydrological cycle
control of erosion
maintenance of the energy flow through the ecosystem
maintenance of biogeochemical cycles
transfer of nutrients
pollination of plants
biological control of populations
preservation of biological diversity
storage and supply of water
production of food and animal materials, and
development of human habitat for leisure and culture.
The role of Landscape Ecology in biodiversity Networks?
Landscape ecology has contributed to conservation
biology and can be considered as the study of
interactions between landscape pattern and ecological
processes.
 Seeks to identify relationships so as to maintain delivery of
environmental goods and services.
 Provides a hierarchical framework to interpret structure, function,
change and stability of systems.
 Also seeks to access the integrity of ecosystems i.e. connectivity,
heterogeneity and fragmentation.
Fragmentation
Island Biogeography
Meta-population Theory
Fragmentation associated with Urban and Agricultural
expansion and catogorised into four stages:
1. Unfragmented stage
(<10% destroyed)
3. Fragmented stage
(40 – 60% destroyed)
2. Variegated stage
(10 – 40% destroyed)
4. Relict stage
(> 90% destroyed)
 Maintenance of ecosystem processes requires the flow of energy,
matter, information, physical factors and biotic factors
 Corridors maintain ecological flows and are divided into:
Structural
Functional
Legal
physical
linear elements
Dispersal and/or
Migration
Policy and law
Connectivity
Size, shape
and habitat
Stakeholders
Prioritization Of Corridors
 Actual or historical presence of species dispersion
 Actual or historical presence of species migration routes
 Actual, historical or proposed presence of movements of
individual
Biodiversity or ecological networks?
 Biodiversity vs. ecological network...
 Dichotomy between species criteria
and habitat criteria when
reviewing biodiversity networks
 Role of systematic conservation planning?
Species-based conservation
Habitat-based conservation
Each species distribution
 Secures ecological
is known
Uses one or few target
Species identified as key or
flagship species
processes and services
 Buffers against extinction
 Includes immigration and
emigration processes
Cont...
 Rarity or endemism is critical for systematic conservation
 Concept of complementarity
 Planning using keystone species – biodiversity species approach
 Planning for fragmentation and habitat loss
 Sensitivity and habitat loss
 Prioritization-linked implementation